Xylanase production by Aureobasidium pullulans on globe artichoke stem: Bioprocess optimization, enzyme characterization and application in saccharification of lignocellulosic biomass

Advances in Aureobasidium research: Paving the path to industrial utilization

We here explore the potential of the fungal genus Aureobasidium as a prototype for a microbial chassis for industrial biotechnology in the context of a developing circular bioeconomy. The study emphasizes the physiological advantages of Aureobasidium, including its polyextremotolerance, broad substrate spectrum, and diverse product range, making it a promising candidate for cost-effective and sustainable industrial processes. In the second part, recent advances in genetic tool development, as well as approaches for up-scaled fermentation, are described. This review adds to the growing body of scientific literature on this remarkable fungus and reveals its potential for future use in the biotechnological industry.

Multi-functional xylanase from Aspergillus sydowii: biosynthesis of nanoconjugates, optimization by Taguchi approach and biodeinking potential

The search for effective production of xylanase which is an important industrial enzyme led to the present study that explored xylanase production by Aspergillus sydowii SF through Taguchi optimization that incorporated nanoconjugates in submerged fermentation. Calcium and zinc oxide nanoconjugates biosynthesized by xylanase were characterized via UV-Vis spectroscopy, Fourier transform infrared spectroscopy, and Transmission electron microscopy (TEM). The xylanase-mediated calcium oxide and zinc oxide nanoconjugates with λmax of 374 and 316 nm, respectively, and were 5.32-17.69 nm in size. Xylanase production was improved by 2.90-10.58 folds (64.24-234.15 U/mL) through Taguchi optimization cum nanoconjugates, and ANOVA showed that nanoconjugates contributed 13.62-65.97% to improved production. The xylanase had up to 88.38% deinking activity, with 49.60-84.64% removal of blue color. The remarkable xylanase production, its use to biosynthesize nanoconjugates and biodeinking potentials contribute to the development of versatile biocatalysts with applications in biotechnology, nanotechnology, and sustainable paper production. To the best of our knowledge, this represents the first report of xylanase for biosynthesis of calcium oxide and zinc oxide nanoparticles, as well as nanosupplementation to induce xylanase production, which can open new vista in bioprocess optimization.

Exploitation of Aureobasidium pullulans NRRL Y-2311-1 xylanase in mulberry and rice flours-based gluten-free cookie formulation: Effects on dough properties and cookie characteristics

Xylanases are mainly utilized in bakery industry for the hydrolysis of dietary fiber-based fractions. Their applications in gluten-free products have not been considered before. In the present study, the xylanase produced by Aureobasidium pullulans NRRL Y-2311-1 was utilized in a mulberry and rice flours-based gluten-free cookie formulation for the first time. Effects of various xylanase concentrations on gluten-free dough rheology and cookie characteristics were elucidated. Only rice flour-based cookie and only wheat flour-based cookie formulations were also prepared as comparison. Incorporation of xylanase into all cookie recipes resulted in softer cookie doughs with lower absolute stickiness. The hardness and absolute stickiness of the cookie doughs prepared by the mixture of mulberry and rice flours decreased by the addition of the enzyme into the formulation in a concentration-dependent manner. Enzyme concentrations above 100 U/100 g flour did not provide statistically significant further changes on gluten-free cookie doughs. Incorporation of xylanase into the cookie recipes resulted in increased baking loss and spread ratio in an enzyme concentration-dependent manner for all cookie types. Hardness values of both types of gluten-free cookies decreased by xylanase incorporation. Different effects on fracturability were observed depending on the cookie type and enzyme concentration. Enzyme concentration of 100 U/100 g flour provided mulberry and rice flours-based cookies with a more flexible and softer structure. No significant effects on color parameters of cookies were observed by xylanase incorporation.

Utility of acidic xylanase of Bacillus subtilis subsp. subtilis JJBS250 in improving the nutritional value of poultry feed

Cane molasses has been employed as a cost-effective medium for enhanced xylanase production in submerged fermentation. Bacillus subtilis subsp. subtilis JJBS250 produced xylanase (15.16 U/ml) at pH 4.0, 35 °C and 200 rpm after 54 h using optimized basal medium by 'one variable at a time approach'. Addition of Tween 80 and PEG 4000 also enhanced xylanase production in cane molasses medium. Combined effect of yeast extract, incubation time and PEG 4000 using statistical optimization enhanced xylanase production to 38.60 U/ml, which was 2.54-fold higher than the 'one variable at a time approach'. The efficacy of xylanase from Bacillus subtilis subsp. subtilis JJBS 250 was evaluated in the improvement of poultry feed nutrition. Xylanase addition (10 IU/g feed) enhanced liberation of reducing sugars (95.540 mg/g substrate) after 48 h at 60 °C. Optimization has resulted in enhanced production of xylanase that improved the nutritional quality of poultry feed.